研究了复合高铁酸盐溶液(CFS)氧化降解活性黑(RB5)染料废水的反应条件和降解机理。结果表明:CFS氧化降解RB5的最佳pH范围为pH〈10,并且在该范围内Fe(VI)的反应速率较快。当pH=8-9,CFS投加量为20mg·L^-1时,氧化反应5min和20min时,RB5的脱色率分别为80%和95%。对TOC和COD的去除实验表明,在氧化反应过程中存在有机分子的矿化反应,但矿化速率远低于脱色反应速率。UV-Vis和FTIR结果表明,染料分子中的偶氮基团能被Fe(VI)氧化破坏,并且处理后样品中RB5的特征红外吸收峰消失,说明了染料分子中部分苯环和萘环被破坏,从而使得染料废水的毒性降低、可生化性提高。因此,CFS作为一种高效、低廉的强氧化剂,为染料工业废水的处理提供了一个可行的方法。
Composite ferrate solution (CFS) was used directly in oxidation of azo dye wastewater of C.I. Reactive Black 5 ( RB5 ). The optimal oxidation conditions and degradation mechanism were inves- tigated. The results indicated that the optimal pH for the oxidation was pH 〈 10, and Fe(VI) had higher reactivity in this pH range. For example, with the CFS dosage of 20 mg · L-1 at pH = 8 -9, about 80% and 95% RB5 had been discolored at 5 rain and 20 min, respectively. TOC and COD removal experiments indicated that the organic molecules could be mineralized, but the mineralization rate was much slower than the decolorization rate. UV - Vis and FF - IR results showed that the azo groups could be broken by the oxidation of Fe( VI), and almost all the characteristic absorption bands of RB5 disappeared which indicates the benzene and naphthalene structure had been destructed. The azo dye wastewater trea- ted by CFS has lower toxicity and improved biodegradability. As a strong oxidant with lower cost, CFS has supplied a feasible choice for the treatment of azo dye in industrial wastewater.